What does the Pace Calculator (Running) do?

Calculate running pace, finish time or distance. Supports km and mile splits for 5K, 10K, half marathon and marathon. All calculations are performed in your browser using official UK rates and thresholds.

Is this medical advice?

No. This calculator is for informational purposes only and does not constitute medical advice. Always consult your GP or an appropriate healthcare professional for medical guidance.

Are the reference values from the NHS?

Where applicable, this calculator uses reference values and guidelines from the NHS and other UK health authorities. Individual needs may vary based on personal health circumstances.

Pace Calculator (Running)

Calculate running pace, finish time or distance. Supports km and mile splits for 5K, 10K, half marathon and marathon.

Last updated: April 2026 · Source: NHS — Couch to 5K

Distance (km)

Time

Hours

Minutes

Seconds

Pace /km

5:00

Pace /mile

8:02

Total Time

50:00

Speed

12.0 km/h

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

A pace calculator converts between pace (minutes per mile or km), speed and finish time for a given distance. If you know two of these three values, the calculator works out the third. Common UK race distances include parkrun (5 km), 10 km, half marathon (21.1 km) and marathon (42.2 km).

The calculator also generates split times for each kilometre or mile, which is useful for even pacing during a race. It can predict finish times for other distances using the Riegel formula, which estimates that pace slows by a known factor as distance increases.

Enter a distance and either your target time or pace. The calculator shows pace per km and per mile, average speed in km/h and mph, split tables and predicted finish times for standard distances. This helps with race planning and setting realistic targets based on training performance.

Example: Half marathon in 1 hour 50 minutes

Distance: 21.1 km
Pace: 110 min ÷ 21.1 km = 5:13/km (8:23/mile)
Speed: 11.5 km/h (7.15 mph)
Predicted 10 km time: ~51:30
Predicted marathon time: ~3:51:00

Source: NHS — Couch to 5K

Frequently Asked Questions

What does the Pace Calculator (Running) do?: Calculate running pace, finish time or distance. Supports km and mile splits for 5K, 10K, half marathon and marathon. All calculations are performed in your browser using official UK rates and thresholds.
Is this medical advice?: No. This calculator is for informational purposes only and does not constitute medical advice. Always consult your GP or an appropriate healthcare professional for medical guidance.
Are the reference values from the NHS?: Where applicable, this calculator uses reference values and guidelines from the NHS and other UK health authorities. Individual needs may vary based on personal health circumstances.